We will study the basic transduction mechanisms of slowly adapting stretch receptors in a fragment of tracheal back wall and separate their intrinsic neural properties from those dependent upon their mechanical arrangement. The localization of fast adapting irritant receptors along the circumference and in the depth of the larger airways will be established by resection through a bronchoscope. Their responses to several types of stimuli will be correlated with their site and with the presence of the epithelial receptive field in order to determine whether mucosal endings alone account for the response capabilities of the receptor. By recording the airway receptor activity from the receptor cell body in the nodose ganglion we will evaluate their responses under conditions more closely resembling their physiological state, i.e., bearing a normal nervous supply to the airway smooth muscles which are functionally associated with these receptors.